In this paper Optimal Homotopy Asymptotic Method (OHAM) has been used to the flow past a rotating disk. This method is applied to the problem obtained from flow past a rotating disk shows its efficiency and effectiveness. This method control the convergence of approximate solution in a convenient way, when it is compared with other methods of solution found in the literature as Homotopy Perturb...

We have performed several simulations of black hole systems (non-rotating, black hole spin parameter a = 0.0 and rapidly rotating, a = 0.95) with a geometrically thin Keplerian disk using the newly developed RAISHIN code. The simulation results show the formation of jets driven by the Lorentz force and the gas pressure gradient. The jets have mildly relativistic speed (& 0.4 c). The matter is c...

The instability modes of the infinitesimally thin self-gravitating disk, which is composed of rotating and non-rotating parts, are investigated. By solving the dispersion relation numerically under various physical situations, two growing modes are found. They are the modified Jeans mode of rotating component or non-rotating one and the Landau mode by wave-particle (non-rotating component) inte...

Recent numerical simulations and analytical models of magnetically collimated plasma outflows from a uniformly rotating central gravitating object and/or a Keplerian accretion disk have shown that relatively low mass and magnetic fluxes reside in the produced jet. Observations however indicate that in some cases, as in jets of YSO’s, the collimated outflow carries higher fluxes than these simul...

I analyse the relativistic accretion phenomena around rotating black holes and neutron stars and show both the kinds of disk can be treated in an unified manner. The corresponding accretion disks are described by pseudo-Newtonian approach. For this purpose, number of pseudo-Newtonian potentials are in literature, applicable to describe the relativistic properties of accretion disk. While, Kerr ...

We present similarity solutions that describe the runaway collapse of a rotating isothermal cloud and its subsequent inside-out collapse. During the runaway collapse, the surface density of the disk is nearly constant in the central part and inversely proportional to the radius in the tail. As the central surface density increases by collapse, the central high surface density part shrinks in ma...

Context. Previous molecular gas observations at arcsecond-scale resolution of the Seyfert 2 galaxy M51 suggest the presence of a dense circumnuclear rotating disk, which may be the reservoir for fueling the active nucleus and obscures it from direct view in the optical. However, our recent interferometric CO(3-2) observations show a hint of a velocity gradient perpendicular to the rotating disk...

The objective of this study was to assess the feasibility and reliability of using miniaturized disk dissolution apparatus for intrinsic dissolution rate (IDR) measurement in the early drug discovery process when bulk drug supply is very limited. The two apparatus, a miniaturized rotating disk system (mRDS) and a miniaturized stationary disk system (mSDS), were evaluated using chloramphenicol a...